Pneumatic weft detector for looms



E. R. HOLMES PNEUMATIC WEFT DETECTOR FOR LOOIIS Nov 29, 1927.

Filed Auz.29.1925

Patented Nov. 29, 1927.

UNITED. STATES 1 1,651,123 PATENT OFFICE. I

'EL'BRIDGE R. HGLMES) 9E \VQ'RCESLER, MASSACZ IUSETTS, 'ASSIGNG-R TO CRQMPTON-BG KNOWLES LOOM WORKS, 038" RVORGESTER, MASSACHUSETTS, -;A CORPORATION OF .ilIASSACI-IUSETTS.

ENE-ETMATIC DETECTOR non Looms.

Application filed assumes, 1925. SeriatNo. 52,245.

This invention relates to weft detectors for weft replenishing looms and it is the general object'ot the invention to provide adetector having a soft 'yieldable portion to'engage the yarn so constructed as not to abrad-e the yarn.

In the 'weaving'of very line yarn suohas' silk bobbin may remain in action long enough 'to cause objectionable wearing oi the yarnwhen the usual iorni of detector is usedf In'order to reduce th'e'impact between the yarn and the detector 1 make the latter of a yielding material such as rribber and depend for "its operation upon the ability or" the detected surface "to allow air 'to [pass theretlirough.

It isa further o'bject-o't my inventionto p'rovide a detector to engage the yarn oi? the bobbin and operableto give an indication or weft exhaustion Upon a marked re-' duction in thepernieability 01 the detected surfacetothe passa e of air.

With these and other objects in view which will appear as thedescription proceedsmy invention resides in the combination and arrangement of parts hereinafter describedand set forth in the claims. V In the accompanying drawings wherein a convenient embodiment of my invention isfshow n,

Fig. 1 is a topplan view of my detector, parts ofthe same being shown in section and the detector being in position to indi catesubstantial exhaustion of filling, Fig. '2 is a view 'Silllllitlfl'O Fig. 1 but showing-the detector-in non-indicating position,

Fig. 3 isa vertical section on line 3-. O l 1,

Fig. l is a perspective VlGW ot'the engaging tip for the teelier, and

Fig. 5"is a reduced vertical'section on line 5''=5 of Fig. 1. I

In carrying out my invention'l provide a detector stand having an upstanding arm 11 provided With'a slot '12 dispose'dvertic'ally in the armll toreceive lever 13 mountedtor reciprocation therein. A controller pin 14: passes through'the rear --poryarn tion of the arm 11 and is providedwith a piston 15 fitteclsnugly in I a bore 16 formed in the arm'll. A 'lig-ht spring 17 is interposed'bet-ween the 'arm- 11 and the piston and acts normally tomove the controller {pin 14 from under the lever 18. WVhen'said lever is fr'ee'to move downwardly no indication is given but when the controller pin 14- is moved thereunder said pin becomes a rolling pivot 'for the lever and the motion 01 the latter is altered in such a way as to eii'ect indication of 'wet't exhaustion. The n'ia'i'iher in which said lever operates to set the replenishing mechanism is set forth in Patent No. 1,030,748 to 'whicli're ference may be had for a furtherdescriptionthereof.

Projecting upwardly :trom the stand 10 and spaced from the arm ll'is a-second arm 18 (see 5) to which'is secured a screw 19. A feel'er bed 20 has depending therefrom .a 'lug' 21 which 'has pivotal connection .-with .the scre'w'l9, "the latter beingturned to move the fe'eler bed toward or from the arm 11. A cap 22is securedtolthebed 20 and defines with the latter a cylinder23. A pipe 24 threaded'into the forward end of thebed and the'cap is connected to one end of a rubber tube 25 the other end of Iw'hich-is-c'onnected to a second'pipe 26 soldered or-otherwise secured to a threaded nipple 27. By means of the matter thus far described compression of air-in the cylinder 23 will move the controller 14 under the lever 13.

Compression of air-in said cylinder 23 is accomplished by meansoi a plunger 28 whihiits snugly in said cylinder and extends rearwardly beyond the end of the cap andbed 22 and 20 respectively. As shown in Fig. 3 the rear end of said plunger is flattened as at 29 and hastightly fitted thereover a fleXible'col-lar-or sleeve 30 torn'ied preterably'of soft rubber. An air passage 3lextendsthrough the plunger28 and connects the cylinder 23-with tl-ieatmosph-ere. An arm 32=projects laterallytronrthmplunger 28 "and has extending therethr'ough a guide pin 33-ar0und which is' disposed acoil spring 34. The latter extends between "the I Fig. 1 having a narrow orifice positioned to engage the surface of the bobbin.

Under normal conditions when there is sufficient yarn for continued weaving as indicated in Fig. 2 the collar will engage the weft of the bobbin to form an air chamber therewith and as the shuttle moves forwardly the plunger 28 will be moved to compress the air in cylinder 23. Because of the amount of yarn present the compressed air will be able to escape between the coils of yarn on the bobbin. Plunger will therefore remain in normal position to keep the controller pin l i out of the path of the lever 13. As the layer of yarn becomes thinner more resistance is offered to the passage of air through the yarn and when the yarn is substantially exhausted as indicated inFig. 1 the air will not be able to escape as fast as it is compressed and will move the piston 15 and place the controller 14: under the lever 13. This condition, as previously described, is attended by a change in the operation of the loom. As the lay recedes the bobbin will move away fromthe collar to establish connectionbetween the cylinder 23 and the atmosphere, after which the spring 17 will restore controller 14. to its normal forward position out of the path of the lever 13.

From the foregoing it will be seen that I have provided a weft detector having a yarn engaging tip formed of easily compressed material such as soft rubber and that at substantial exhaustion of weft said tip forms an air tight connection with the bobbin to prevent the escape of air which is compressed as the advancing lay moves the plunger 28 forwardly. The air passes through the coils of yarn without injury to the same and there is substantially no change in the behavior of the flexible collar 30 as exhaustion of yarn approaches.

Having thus described my invention, it will be apparent that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention, and I do not wish to be limited to the details herein disclosed, but what I claim is:

1. In a weft detector for looms, a surface to be detected, a member deformable to the shape of the surface to be detected and having an opening therein for the passage of air, and means pneumatically connected with the opening in the member to prevent the indication ofwveft exhaustion when air can pass from the member througl'r the surface to be detected and effective to indicate exhaustion when air cannot pass from the member through the surface to be detected.

2. In a weft detector for the bobbins of looms, an air cylindena plunger having a portion thereof movable in said cylinder, a hollow yieldable member mounted on said plunger to engage the surface of the bobbin to be detected and deformable to the shape of said detected surface to form with the latter an air chamber, said plunger having I cylinder and the air is prevented from pass ing from the air chamber through the detected surface.

8. In a weft detector for looms, a cylinder, a plunger mounted substantially air-tight therein, a yieldable member mounted on the plunger in position to be engaged by the surface to be detected, said member forming with the detected surface and adjacent portions of the plunger an air chamber, a second cylinder, a piston mounted in said second cylinder, and means under control of the piston to indicate substantial exhaustion of Weft, said plunger having an air passage therethrough communicating with the air chamher and the cylinder, and said'cylinders being pneumatically connected together.

In a pneumatic weft detector for the bobbin of a. loom, means defining an air chamber, a piston movable in the airchamber, means to indicate weft exhaustion connected pneumatically with the air chamber and operable when air is compressed in the chamber, and a deformable member carried by the piston and engaging the. bobbin, said piston having an opening extending therethrough from the flexible member and communicating with the chamber, the flexible.

member deriving movement from the bobbin and imparting movement to the vpiston'to compress the air in the chamber, the compressed air escaping through the bobbin when sufiicient weft is present and being prevented froinescaping by contact of the flexible member with the bobbin to actuate the indicating mechanism.

5. In a pneumatic Weft detector for the bobbin of a loom, a member movable under influence of the advancing bobbin, means defining an air chamber in which the. member moves said member having a deformable end to engage the bobbin, said member having a passage therethrough connecting the chamber with the air adjacent the bobbin,

and indicating mechanism pneumatically connected to the chamber, said member compressing the air in thechamber on all advancing movements of the bobbin, the comressed air esca ain to reventindication of weft exhaustion when sufficient weft is present and being prevented from escape by contact of the flexible member with a substantially denuded bobbin to close the passage in the member to cause indication of weft exhaustion. r

6. In a pneumatic weftdetector for the bobbin of a loom, movable means to compress air and deriving its movements from the advancing bobbin each time said means is engaged by an advancing bobbin, a'de-' formable device connected to the means and engaging the bobbin, the air compressed by movement derived from the bobbin as the latter advances escaping through the deformable device and a supply of Weft sufiicient for continued Weaving and being held against escape by the contact of the deformable member With the bobbin when insuflicient Weft for continued Weaving is present, and a device pneumatically connected to said means to indicate Weft exhaustion when the compressed air is unable to escape.

7. In a pneumatic Weft detector for the bobbin of a loom, a regularly moving actuator, a pneumatically operated controller therefor normally out of the path of the actua-tor and movable into the path of the actuator when acted upon by compressed air, means defining a chamber pneumatically connected to the controller, a member movable in the chamber to compress the air therein and having an opening therethrough connecting the chamber to the atmosphere, and a deformable element to engage an adopening in the member, thereby causing compressed air to move the controller into operative position With respect to the actuator.

-8.In a pneumatic Weft detector for the bobbin of a loom, means defining a chamber, a member movable therein to compress air, said chamber normally being open to theatmosphere, deformable means carried by the member to prevent escape of air from the chamber at the time of substantial exhaustion of Weft to compress the air in the chamber, and means effective When air is compressed in the chamber to indicate substantial Weft exhaustion.

In testimony whereof I have hereunto affixed my signature.

' ELBRIDGE R. HOLMES. 

